1. Field
The described technology relates generally to an organic light emitting diode (OLED) display and a method of manufacturing the same.
2. Description of the Related Technology
An OLED display includes OLEDs made up of a hole injection electrode, an organic emission layer, and an electron injection electrode. Each OLED emits light which is generated when an exciton generated by combining electrons and holes in the organic emission layer falls from an exited state to a bottom state.
Since the OLED may deteriorate by external factors such as external moisture, oxygen, or ultraviolet (UV) rays, a packaging technology which seals the OLED is needed, and the OLED display needs to be thin or manufactured to be easily bent, so that the OLED display can be used in various applications. A thin film encapsulation (TFE) technology has been developed in order to seal the OLED and thinly form the OLED display to be bent. The thin film encapsulation technology is a technology in which one or more inorganic layers and organic layers are alternately laminated on the OLEDs formed in a display region of a display substrate to cover the display region with a thin film encapsulation layer. In the case where the display substrate of the OLED display having the thin film encapsulation layer is formed of a flexible film such as polyimide, the display substrate may be easily bent and may be thin. In the case where the display substrate is formed of the flexible film, a barrier layer is formed on the flexible film and the OLED is formed thereon in order to prevent external moisture from flowing from the outside through the flexible film and gas from being generated from the flexible film.
However, since polyimide is a material having high viscosity, which is applied and then cured to be manufactured as the flexible film, a protrusion portion or a recess portion may be formed on the surface of the flexible film by particles when the flexible film is applied. The protrusion portion or the recess portion of the flexible film may apply a damage to the barrier layer thereon to generate cracks on the barrier layer. Accordingly, external moisture may seep through the cracks of the barrier layer, damaging the OLEDs, and causing dark points and the like in the OLED display.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the described technology and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.